Improve mkcloud offline instructions
Improve mkcloud offline instructions

Add want_cached_images environment variable to the sample script.

SUSE-Cloud/automation,gosipyan/automation,aspiers/automation,gosipyan/automation,SUSE-Cloud/automation,aspiers/automation,gosipyan/automation,SUSE-Cloud/automation,SUSE-Cloud/automation,gosipyan/automation,aspiers/automation,aspiers/automation